1. Field of the Invention
The present invention relates to tape cassettes and more particularly to a novel and highly effective tape cassette for use in a magnetic recording and reproducing device such as a videotape recorder, the tape cassette having a tape wound in coils of small diameter so that a magnetic recording and reproducing device that employs the tape cassette may be of a reduced size.
2. Description of the Prior Art
There have been proposed tape cassettes for use in magnetic recording and reproducing devices such as videotape recorders (VTRs), the tape cassettes being designed particularly for recording information during a relatively short period of time. The proposed tape cassettes have a cassette housing that accommodates a magnetic tape wound in coils of small diameter, thereby enlarging a mouth in which a head drum and related portions of a cassette player can be partially inserted, so that the magnetic recording and reproducing device may be reduced in size. Reference should be made to Japanese laid-open patent publication No. 60(1985)-171684 and Japanese utility model application No. 62(1987)-14573 filed by the assignee of the present application.
One such tape cassette for recording information in a short period of time is schematically shown in FIG. 9 of the accompanying drawings. In FIG. 9, the tape cassette has a cassette housing 51 accommodating a pair of rotatable tape reels 52, 53 with a magnetic tape T wound therearound. The magnetic tape T has a portion unreeled from the tape reels 52, 53 and guided by semicylindrical guides 54a, 54b disposed in spaced positions at the front of the cassette housing 51, the unreeled tape portion being kept taut and exposed in a front opening in the cassette housing 51. The cassette housing 51 has a mouth (opening) 55 formed in a lower panel of the cassette housing 51 between and somewhat forward of the tape reels 52, 53.
The diameter of the tape reels 52, 53 is smaller than the reel diameter of a conventional, standard tape cassette, and therefore the mouth 55 is correspondingly larger.
When the tape cassette is in use, the magnetic tape T is withdrawn forwardly from the cassette housing 51 by tape withdrawal guides 60a, 60b in the magnetic recording and reproducing device, and a head drum 61 and various tape transport members 62 including an impedance roller 63, tape guides 64, 65, 66, loading posts 67, 68, a capstan 69, and a pinch roller 70 are inserted to the extent feasible into the mouth 55. The magnetic tape T is now wound or loaded around the head drum 61 for recording or reproducing signals on or from the magnetic tape T.
Since the tape reels 52, 53 are smaller in diameter and the mouth 55 is correspondingly larger than in earlier tape cassettes of the same general construction, the head drum 61 and the tape transport members 62 can be inserted deeply into the cassette housing 51. As a result, the magnetic recording and reproducing device may be made small.
However, the increase in the size of the mouth is slight since only the diameter of the tape reels is reduced in the conventional tape cassette for recording information during a relatively short period of time. This limits efforts to reduce the size of the magnetic recording and reproducing devices.
In a conventional tape cassette, the cassette housing contains unused space near the rear corners of the tape reels; the space in the cassette housing of the conventional tape cassette is thus not effectively utilized.